I’d say start over again. The reboot was just a big shoot out in a tower block, and might as well have been a remake of The Raid or something. It just didn’t go anywhwhere and the action scenes were second rate compared to The Raid.
Stallone’s one had a bigger more epic story and brought in more characters from the comic book.
The scenes I loved from the Stallone Dredd were the ones with the Angel Family… admittedly, most of the rest of the movie was utter sh*te! :)

The original plan was for a trilogy with the sequel looking at the development of the Megacities and Dredd himself and then the 3rd to be the Dark Judges.

I don’t think a reboot is needed though, just a bigger story. I’ve no doubt confining all the action to the tower block was a budgetary decision (Coincidentally the current Dredd story line in 200AD is about Dredd working as a block judge). There’s a lot of stuff hidden away in the film though – the Chopper graffitti, the radio call about Hershey – that points to a bigger universs they just couldn’t afford.